Safety connection



F615- 1934- J. D. MCCLINTOCK SAFETY CONNECTION Filed Jan. 18, 1933 why/ N fining ,[Z

Patented Feb. 27, 1934 PATENT OFFICE SAFETY CONNECTION John D. McClintock, Philadelphia, Pa., asslgnor to William Sellers & Company Incorporated, Philadelphia, Pa., a corporation of Pennsylvania Application January 18, 1933. Serial No. 652,333

4 Claims.

This invention relates to a safety connection between a water column and a boiler designed to avoid boiler explosions or lesser damage occasioned by a falling of water level below a critical point which may not be noticed on a gauge attached to the water column or determinable by opening of the usual gauge cocks.

The invention relates'particularly to the provision of a form of connecting nipple designed to prevent stopping of the connections between a boiler and a water column. The arrangement will be apparent from the following description read in conjunction with the accompanying drawing in which:

Fig. 1 is a fragmentary sectional view showing a boiler, a water column and the connections between the two; and

' Fig. 2 is an enlarged sectional view through certain portions of the connections.

Referring first to Fig. 1, there is illustrated at 2 the top of a boiler shown in the present instance as a locomotive boiler while 4 indicates the crown sheet of the same. In a boiler of this type it is necessary for safety that the .water level should always be above the crown sheet. In order to give indication of this there is attached to the boiler the usual form of water column indicated at 6 provided with a plurality of gauge cocks indicated at 8, the uppermost and lowermost of which are above and below normal water level.

A gauge glass 10 is connected at its upper endwith the water column through a gooseneck 12 and an upper valve 14'. At its lower end the glass has connections with the water column through a valve 16. The lower end of the water column is connectedto a water leg of the boiler through connection indicated at 18 while its upper end communicates with the steam space of the boiler through the conduit illustrated at 20.

Referring now more particularly to Fig. 2 the conduit 20, taking the form of a pipe, is threaded into a nipple 22 which is provided witha flange 24 resting upon an outwardly facing seat formed at the upper end of a union 26 threaded into the top wall of the boiler. A coupling nut 28 serves to clamp the flange 24 against the seat.

Heretofore the nipple 22 terminated at the level of the lowermost face of the flange 24. Considering the nipple of this old type, everything so far described constitutes the usual conventional structure.

The conventional structure is dangerous for the following reason which has resulted definitely in at least one boiler explosion resulting in the loss cl 9. number of lives and great damage toprop- 'erty. "The danger arises in view of the fact that when the boiler is tested for its ability to withstand pressure the steam gauge connections are removed leaving in position, however, the union 26. In order to close this union a solid washer is located on the seat thereof and clamped down against the seat by either the coupling nut such as 28 normally used for making the connection with the water column or a cap. These connections in a locomotive are normally at a fairly inaccessible position and following a pressure test a careless workman is likely to remove the coupling nut or cap but may fail to remove the washer. He may then without noticing anything wrong place on top of the washer the nipple and secure it in position by the clamping nut tions willremain the water column indicating a full boiler. If eventually thecrown sheet is uncovered a disastrous explosion may result. The conditions just outlined were those determined as having existed in at least one instance. In accordance with the present invention the usual nipple is modified by the provision of an extension 30 which may, as shown, take the form of a tube or may alternatively consist of one or more prongs extending downwardly beyond the flange 24. The minimum length of this extension should be such that if a washer obstructed the free passage through the union at the level of the seat, the flange 24would not move downwardly sufliciently to permit the coupling nut to be engaged with the threads on the upper end of the union. Preferably, however, this extension is of greater length and may be of the length indicated in which it extends completely through the union into the. boiler. This would prevent any connection of thecoupling nut which might appear to be satisfactory as long as any obstruction existed within the union 26 since a washer or the like might possibly be forced downwardly below the seat but would still be held frictionally within the bore of the union and be jammed into a stoppage position by the pressure of steam. It will be obvious that the construction described insures the non-occurrence of the conditions outlined above which are likely to cause an explosion.

Instead of having the safety extension 30 secured to the nipple 22 it may form an extension of the pipe 20 and as indicated above may take the form of either a complete cylindrical extension of the pipe or one or more prongs extending either beyond the seat of the union 26 or within the boiler.

What I claim and desire to protect by Letters Patent is:

1. In combination, a boiler, a water column, and upper and lower connections between the water column and the boiler, said upper connections including a union adjacent the boiler provided with an outwardly facing seat, a nipple having a flange, and a coupling nut threaded on said union and arranged to clamp the flange of the nipple upon said seat, said connections including a safety extension projecting within the union inwardly of said seat when the parts are assembled.

2. In combination, a boiler, a water column, and upper and lower connections between the water column and the boiler, said upper connec-' tions including a union threaded into the boiler provided with an outwardly facing seat, a nipple having a flange, and a coupling nut threaded on said union and arranged to clamp the flange of the nipple upon said seat, said connections including a safety extension projecting through the union into the boiler when the parts are assembled.

3.In combination, aboiler, a water column, and upper and lower connections between the water column and the boiler, said upper connections including a union adjacent the boiler provided with an outwardly facing seat, a nipple having a flange, and a coupling nut threaded on said union and arranged to clamp the flange of the nipple upon said seat, said nipple having a safety extension projecting within the union inwardly of said seat.

4. In combination, a boiler, a water column, and upper and lower connections between the water column and the boiler, said upper connections including a union threaded into the boiler provided with an outwardly facing seat, a nipple having a flange, and a coupling nut threaded on said union and arranged to clamp the flange of the nipple upon said seat, said nipple having a safety extension projecting through the union into the boiler.

JOHN D.' MCCLIN'IOCK. 

